This invention relates to improved pipe spinners for turning one section of well pipe rapidly relative to another in order to spin the sections into or out of threaded engagement.
The spinners of the present invention are of a known general type including a series of rollers adapted to engage a well pipe at different locations about its periphery in a relation gripping the pipe between the rollers and then driving it rotatively by powered rotation of one or more of the rollers. Copending application Ser. No. 06/257,105 filed Apr. 24, 1981 by Boyadjieff et al. on "Pipe Spinning Tool" shows such a spinner in which two body parts carry rollers at opposite sides of a pipe and are mounted by two pivotal connections for swinging movement about two different axes to move the rollers toward and away from one another and between a closed position of gripping engagement with a pipe and an open position releasing the pipe from engagement with the rollers. In that prior arrangement, the two pivotal connections are desirably attached together by an adjustable connection capable of shifting the two pivotal connections and their axes toward and away from one another and thereby adjusting the spinner for optimum driving engagement with pipes of different sizes. The adjustable connection for varying the spacing between the two pivotal axes preferably includes interengaging threaded parts designed to shift the two axes relative to one another upon rotation of one of the threaded parts. More particularly, the adjustable connection may include two nuts attached to the two pivotal connections respectively and having right-hand and left-hand threads respectively engaging corresponding right-hand and left-hand threads of a third element which acts upon rotation to move the two nuts relatively toward or away from one another.